36a - Inhalation Anesthetics Flashcards
Define analgesia
relief of pain without altered mental state
Defien anxiolysis?
decreased apprehension with no change in level of awareness
What is the Myer- Overton hypothesis?
anesthetic activity i directly linked to lipid solubility. This is mostly true, but not the whole story.
What is the blood:gas partition coefficitent and how does it impatct anesthesia?
if blood/gas partitoin is 2.3, this means that at equilibrium, when there is 2% in the gaseous delivery, it will occupy 4.6% of the blood. It takes longer to get up to that concentration..
Lower blood/gas partions mean drug reaches effective concentration in blood faster.
What can be clinically done to hasten unconsciousness?
??
Define MAC
minimum alveolar concentration. Concentration in inspired gas required to render 50% of people unconscious.
What are the special problems related to nitrous oxide?
??
In general, which anesthetics are more potent: lipids or water solubles?
lipids. More lipophilicity = more potent usually.
What is most common pathway of action for inhaled anesthetics?
stimulation of GABA and glycine inhibitory signalling, reinforcement of two pore potassium channel activity and inhibition of glutamatergic signalling.
What is the purpose of the addition of a halogen like fluorine to volatile agents?
to prevent explosion.
If a volatile agent is given at 5% mixture with oxygen and N20, (atmospheric pressure is 760mmHg), then what is partial pressure of halothane delivery
5% of 760 is 38
Which will have quicker recovery after anesthesia: halothane or sevoflurane?
sevoflurane will have both a faster onset and recovery. Halothane sucks. Dick
Which drug will respiration rate have a more profound effect on uptake time: halothane or sevoflurane?
sevoflurane. Halothane sucks. Dick
Which inhaled anesthetic does NOT inhibit protective PaCO2 reflex?
Nitrous oxide. note, others can kill because this is suppressed.
What happens to BP and CO with increasing anesthesia?
decreased BP and CO.
What effect does nitrous oxide have on BP and CO?
none, unless used in conjunction with another inhalant.
Which new inhalant supposedly has no irritating odor?
sevoflurane. the king of anesthetics apparently
Which inhalants can have hepatotoxicity?
halothane. sucks. dick
and enflurane
Which inhalant can cause seizures?
enflurane
What deleterious effect can N20 have that could be dangerous for vegetarians?
it inhbits vitamin B12, which they could already be deficient in. Can lead to myelin sheath degeneartion.
What is teh second gas effect?
N20 has such high solubility that it tends to carry other inhalants in with it. so other drugs will accumulate more rapidly than they would alone.
What is diffusional hypoxia?
when the anesthetic is turned off, large quantities of anesthetic gas exit the lugns. In order to maintian adequeate perfusion, oxygen must be supplemented.
